A hydraulically driven gob distributor for IS and RIS container making machines can be associated with a reversing valve, switch valve, or change-over valve.
IS machines for the production of hollow glass articles are equipped with gathering or preform molds and with pertaining finishing molds for these. Characteristic of such IS machines is that in each of the sequentially operated stations the same operations are performed in a sequential or timed manner in a predetermined pattern or cycle.
In general terms, the production sequence for hollow glass articles includes feeding the molten glass gob into a metallic gathering mold of the individual station, and pressing, blowing, blow-molding, etc. of the so-called parison. On transfer of the parison formed from the gob to the finishing molds of the respective stations, the ultimate shape is obtained by further blowing or evacuating of or at the exterior thereof.
Usually up to three molds are provided in the preliminary or gathering mold complex, i.e., single, double or triple molds, respectively. A similar grouping is then provided at the finishing mold section of a production station of an IS machine. The other stations of the machine are equipped in analogous manner. The individual production stations are linearly arranged. In the case of the RIS machines the finishing molds are arranged on a rotating table, whereby each gathering mold has at least two associated finishing molds.
The gob distributor for such machines for the production of glass articles feeds individual portions, i.e. gobs, of a continuously exiting fluid strand of glass into the individual channel or troughs of the stations of an IS, or RIS machine.
The gob distributor carries out swinging movements or oscillations which must be carried out with high precision and speed, so that under the conditions of high production rates, the glass gobs are deposited with sufficient accuracy in the inlet channels of the production stations of the machine. Within the predetermined angle of oscillation the gob distributor stops several times in accordance with the number of the production stations which are to be supplied with glass gobs. The sequence of the stops should be freely selectable within the maximum angle of oscillations for greatest versatility. The gob distributor is equipped with an oscillating drive whereby an adjustable control serves to attain the stop or unload position at the predetermined location.
The efficiency of such a gob distributor is a function of the velocity of the swinging movement and the accuracy of the holding or stop positioning. The use of various forms of drives depends on the type of energy input. As well, the control of such drives can be done using various energy media and, consequently, the lay-out of these varies as well.
A control system is described in Swiss Pat. No. 523 855 in which a mechanically driven and continuously rotated cam disc actuates a cam rod or impact rod. This rod actuates, in turn, the gob distributor. The positioning accuracy and the efficiency of this apparatus are largely influenced by the masses to be moved, the contact pressure of the rod, and the wear of the cam disc. In such apparatus, accordingly, use is made of a mechanical drive and a mechanical converter.
German patent publication DE-OS No. 2 501 109 describes an apparatus in which a mechanically driven cam disc operates a push rod. This rod actuates gear wheels and pinions, which in turn are operatively connected to a hydraulic valve. In this apparatus, accordingly, the gob distributor is mechanically driven and the control is achieved by mechanic-hydraulic means.
It is of disadvantage in such prior art apparatus that it is required to move relatively large masses, associated with at least temporary inertia and with insufficient accuracy due to the selected control media, during positioning in the stop positions of the gob distributor. The result is limited quality and productivity of the glass articles to be produced.
Considerable improvement is achieved with the apparatus according to German patent publication for an application DE-OS No. 31 13 267 corresponding to the PCT application. This apparatus includes a hydraulic actuated gob distributor, whereby the control of the hydraulic drive is achieved by a change-over (reversing) valve which, in turn, is actuated by an electronic computer and processor.